Tweet
I will find time soon Lamoiz and let you know. Hope you find a lot of good things with your ANPI and lucky coil, Regards, Marty.
-
-
Dear Qiaozhi and all, I build the Nano metal detector and it works charming! I started with a breadboard but finally bought the PCB at DiyDetector store which is of excellent quality! I also enjoyed the related Surf Detector video's. Very helpfull in testing and adjusting the metal detector. I would like to express my thanks for your great book. At the moment I am also reading the Voodoo Project book and considering building that one too. DiyDetector has the PCB but not the Nano Voodoo adapter. Also figuring out how to make a reasonable TX- and RX-coil... Keep up your work, it's genious!Comment
-
-
How to get the pdf of the book "Arduino nano PI metal detector"?Comment
-
There is no e-book version available.Originally posted by Hamza Aamer1 View Post
You can buy the printed version from Amazon -> Arduino Nano Pulse Induction Metal Detector Project - Published March 2021
Comment
-
Pick up a "Detech 8″ Mono closed design gold coil" for my NanoPi. This coil is intended for the Minelab GPX series. On the bench this coil is AMAZING. But in the field it's worthless. It is constantly ringing. Most pronounced at the beginning of every sweep. When I do pass over a metal target, the signal suddenly goes away, until my sweep changes direction and I start sweeping back in the other direction. I have tried adjusting everything and cant find the correct combination to make this work. Any ideas?Comment
-
Maybe try an adjustable damping resistor? Is your cable shield connected wrong?
Any experience with using the coil on a GPX?
Is scope shot on the bench? That meter looks cool.Comment
-
Scope pic is on the bench. Damping resistor set to 350 ohms, after a bit of tuning to find the sweet spot.
GPX mono coil wiring. So I think I have that right. "Think"
This is a new coil, so I think it should be good.
Coil rings in both direction of the sweep. Does not feel like loose cables or wiggling cables.Comment
-
What do you mean by "ringing?" Part of you symptoms sound like bad SAT behavior. It would help to post an audio recording.Comment
-
If the coil is correctly damped and works well on the bench, but it misbehaves in the field, then it sounds like a shielding problem. Either the screen is not connected or you have the wires swapped over so that the ANPI is transmitting on the screen.Comment
-
Earth field, ground signal and coil shielding can cause false signals. Any others? https://www.geotech1.com/forums/show...094#post292094 appears to be ground signal. What tests can be done to best determine what the problem is? Maybe a problem is something stupid. Was testing on the bench the other day and wasn't getting what I expected when I moved a target close to the coil. The problem was a new shirt I got for Christmas, had metal snaps on the sleaves instead of plastic buttons.Originally posted by Qiaozhi View PostComment
-
Swapped the coil wires and does not seem to make a difference. This is a know good ANPI build. With a simple home brew coil, it works great. So I am 98% sure this is all related to the new GPX coil.
Lets see if I can better describe the issue. As best as I can tell, this is some kind of interaction with the ground. When I hold a target up in the air and sweep over it, everything works as expected. If I can pull of a sweep with almost zero height change between the coil and ground, the ANPI is mostly quite.
Does anyone have the wiring/pinout for the GPX mono coil. Or first hand knowledge of what's inside said coil?Comment
-
i think the gpx coil is more sensitive and you are detecting minerals in the ground. Did you try to adjust delay higher to see if still have false signals?Originally posted by dingbatca View PostComment
-
I would not be surprise if the coil was/is picking up ground minerals. Sure feels like it. I swept my test location with two other (VLF) detectors to make sure it's clean of obvious targets. I have extensively messed with the delay and threshold trying to find the correct combination. No luck.
Any other ideas?Comment
-
So that definitely narrows it down. It could be:Originally posted by dingbatca View Post
1. Ground mineral pickup -- might go away with a larger delay unless it is a viscous effect. If it's viscous ground, you will need a PI with GB.
2. Ground capacitance pickup -- only likely if the coil shield is bad. If you are swinging over grass then move to a dry dirt-only spot. Don't rub the coil on the ground.
3. Earth field -- is easy to tell just by raising the coil and twisting it in the air.
I'm still bothered by this statement:
This might happen if the SAT circuit gets stuck on a bounce-back signal. But then you say a home-brew coil works fine. Puzzling.When I do pass over a metal target, the signal suddenly goes away, until my sweep changes direction and I start sweeping back in the other direction.Comment
Comment